Screens have long been used in combination with sand or other proppants to hold open perforations in a formation and to prevent production of particulates from the formation from clogging up the production screens. The common procedure for doing this is known as gravel packing. Eventually, the concept of screen expansion took hold as a possible alternative to gravel packing. In this more recent development, the annular space around the screen was eliminated due to its expansion. The borehole wall would then be in contact with the outermost layer of the screen and the need to deposit sand or other proppants was eliminated in certain applications. Expanding screens are illustrated in U.S. Pat. No. 6,263,972.
Previously, when gravel packing screens, it was known to provide a control line or conduits for a variety of reasons. Conduits running along a screen could be used to move gravel around a sand bridge during deposition of gravel. Such conduits could also carry fiber optics for the purpose of communicating downhole conditions to the surface. This concept is illustrated in U.S. Pat. No. 6,409,219. Methods for fabricating screens have also been developed. For example, U.S. Pat. No. 6,305,468 illustrates joining layers of a non-expanding screen by putting the layers through a die after rolling them together. This technique allowed welds to be eliminated to improve the reliability of the finished product.
The prior designs did not address the issue of how to provide surface communication of downhole conditions when using an expanding screen. There are special conditions to consider when providing a communication conduit in conjunction with an expanding screen. The screen tends to shorten in length as it is expanded. The screen is expanded into a borehole wall. The communication conduit is exposed outside the screen during run in and could get damaged. These issues are all addressed by the present invention. The nature of the solutions will be more apparent to those skilled in the art from a review of the description of the preferred embodiment and the claims, which appear below.